Agree with all comments. Just will add that specifically for novices and generally for anyone is better to use these commands so that you will understand what the code is doing in real time

Code:

ftn95 b1god.f90 /link /checkmate >zzz

where zzz will be compiler generated file containing errors, comments and warnings. And the /checkmate (same as /undef) is one very nice debugging option, do not use it when the code will be completely error-free as it slows down the execution.

Then if b1god.EXE file will be created run it via debugger

Code:

sdbg b1god.exe

and hitting F7 see step by step execution of your program. Other debugger's commands are in the menu and are are completely self-explanatory to anyone including your dogs and cats (most of computer games children play today are
infinitely more complex and no one ever RTFM)